Systems composed of multiple, interconnected plastic bags have met widespread use and acceptance in the collection, processing and storage of blood components. Using these systems, whole blood is collected and separated into its clinical components (typically red blood cells, platelets, and plasma). The components are individually stored and used to treat a multiplicity of specific conditions and diseased states.
Before storing blood components for later transfusion, it is believed to be desirable to minimize the presence of impurities or other materials that may cause undesired side effects in the recipient. For example, because of possible reactions, it is generally considered desirable to remove substantially all the leukocytes from blood components before storage, or at least before transfusion.
Filtration is conventionally used to accomplish leuko-reduction. Systems and methods for reducing the number of leukocytes by filtration in multiple blood bag configurations are described, e.g., in Stewart U.S. Pat. No. 4,997,577, Stewart et al. U.S. Pat. No. 5,128,048, Johnson et al. U.S. Pat. No. 5,180,504, and Bellotti et. al. U.S. Pat. No. 5,527,472.